In general, devices utilizing a mercury intrusion method or a bubble point method are applied in order to measure the physical properties of a porous material, such as a porosity, an average pore diameter, and a pore distribution (see, for example, Patent Literature 1).
The mercury intrusion method is a method defined in JIS (Japan Industrial Standards) R 1655 (2003). Moreover, the bubble point method is a method defined in JIS K 3832.
In addition, a method is also known which, for example, obtains a pore diameter through an observation of the surface of a porous material using a microscope.
A DPF (Diesel Particulate Filter) constituted by a porous material represented by ceramics is recently getting attention as a device for eliminating particle-like materials contained in the exhaust gas from a diesel engine.
In the field of the DPF, the average pore diameter, and pore distribution, etc., of a porous material largely affect the functions, such as a pressure loss and a collection efficiency. Hence, data on the average pore diameter, etc., is used to define a product and is also used as guarantee data.
Data obtained through the mercury intrusion method are normally used as data indicating the function of the DPF so far. The use of mercury is, however, restricted in many countries. Moreover, in Europe, the export of mercury is prohibited after 2011, and it is desired to reduce the usage. Accordingly, a measurement through the mercury intrusion method will be restricted from now on, and may become difficult to carry out.
Conversely, the measurement through the bubble point method and the measurement using the microscope differ in the measurement principle from the measurement through the mercury intrusion method. Accordingly, data obtained through the method other than the mercury intrusion method have no correlation with data obtained through the mercury intrusion method. Hence, a measurement through a measuring method equivalent to the mercury intrusion method in principle is needed to maintain the compatibility with past data or products.
In order to address such a disadvantage, a scheme of causing a computer to simulate a measurement through the mercury intrusion method, thereby obtaining a pore diameter, and a pore distribution, etc., is proposed.